(1) Field of the Invention
The instant invention pertains generally to exercising devices for strengthening the trunk muscles of a human being, and more particularly to an exercising device that operates on a trunk twisting concept.
(2) Description of the Prior Art
Exercising machines for strengthening the trunk, or torso, of the human body are known, as, for example, the exercising machine disclosed in U.S. Pat. No. 3,012,776, granted Dec. 12, 1961 to Leon G. Hotas. Such machine comprises a table 22, a platform 30 pivotally supported from the table for swinging movement, a pulley 31 rotatable on the platform, a manual control 48 for releasably locking the platform to the pulley for joint rotation, and a lifting cable 37 that normally has a weight at one end. The possible end of the cable is windable about the pulley. Backing plates 61 retain a recumbent patient on the platform with the abdominal joints of the patient extending over the pivoted support. By connecting the platform to different positions on the pulley 31, the patient can operate the machine by either pushing or pulling the weights. The rehabilitative aspects of this exercise device are discussed in column 3, line 67-column 4, line 34, and the suggestion that the same exercising device may be used to develop torso muscles for athletes is noted at column 4, lines 35-37.
While the torso exercising device disclosed by Hotas may be well suited for assisting in the rehabilitation of patients with severe spinal and back injuries, such device, which must be used in a supine position, is too bulky, cumbersome, and complex for use in a gymnasium or other athletic training facility. Furthermore, the Hotas device is not suited for developing, or at last toning, all of the several different groups of muscles that are situated about the human spine.